Escapement action for grand pianos



Nov. 16,1943. R, S'CHULZE 2,334,444

ESCAPEMEN'I ACTION FOR GRAND PIANOS Filed Aug. 19; 1942 game/14W REINHARD SCHULZE ey- LJ Patented Nov. 16, 1943 UNITED STATES" PATENT OFFICEESCAPEMENT ACTION FOR GRAND PIANOS Reinhard Schulze, Baltimore, Md.Application August 19, 1942, Serial No. 455,275

5 Claims.

right angles to that motion. After usage the outer padding on theknuckle stretches, both layers of padding get hard and sometimes theyflatten or have a groove or a pit formed in them by the jack head. Whenthis occurs, the padding should be replaced, but in the great majorityof cases, the stretched and compacted knuckle is continued in service,until more serious defects arise, and these take the form of breaking ofthe hammer stem or the hammer shank flange, or at times the knuckle ofthe jack is broken oil. The

keys of the piano are often struck vigorously, and this sudden impact istransferred directly to the hammer knuckle and if the jack cannot strikethat knuckle and slide off, as is intended, the weak part of thesemembers will break. Continuing these stretched and compacted knuckles inuse also diminishes the original sensitive touch of the keys, impairingand limiting concert playing.

The objects of this invention are to construct the knuckle and jack andthe cushioning therebetween so that this stretching, flattening,grooving and pitting of the padding between them will be avoided and sothat, even with age and without replacement the sensitive touch will bemaintained and no breakage of the parts will occur.

Other objects and advantages of the invention will become apparent fromthe following detailed description taken in connection with theaccompanying drawing forming a part hereof, and in which:

Figure 1 is a fragmentary vertical sectional view through a grand pianoaction embodying the novel features of the present invention.

Figure 2 is an enlarged fragmentary view of the hammer knuckle and jackhead.

Figure 3 is a detailed sectional elevation of the parts shown in Figure2, viewed from the right.

Figure 4 is a fragmentary perspective view of a modified form of paddingfor the hammer knuckle.

Referring now to the drawing, I is the piano key, 2 the capstan thereon,3 the wippen engaged by the capstan, 4 is the jack which works through aslot 5 in repetition lever B. The head 1 of the jack engages the knuckle8 on hammer stem 9. Upon striking the key I, and before it returns toits position of rest, the jack 4 strikes knuckle B and throws the hammerup, before it strikes the wire or piano string, jack knuckle l strikingits button ll, causes the jack head I to slide from and be disengagedfrom hammer knuckle 8, and after striking the wire, the hammer head I2comes to rest on back check head I3. When a key is struck hard, thehammer stem 9 atits small section and at its hinge, and the hammerflange I and the jack near the knuckle 10 are subjected to severestrain.

Knuckle 8 has usually been double cushioned and the head I of the jackwas not cushioned,

and as the head is dug into the cushion on knuckle B, and was drawnacross it, the head stretched, compressed, grooved and pitted thecushion until the head no longer easily slid from knuckle, the sensitivetouch was lost and strain was added to the parts named and one of themoften broke.

By this invention the knuckle 8, in the pre- 'ferred form, has a roundrigid center l6 and the head I of the jack is cushioned by an underlayof cloth I! and an overlay of leather H3 in such manner as to present afiat face to strike the knuckle 8. Even should the cushion on head 1 becompressed it will not groove or pit, it will remain flat, and it willalways perform its function of striking the knuckle and easily slidingtherefrom when moved at right angles to the face of the knuckle 8 whichwas struck, because of the knuckle ID of the jack striking its button Il. The sensitiveness of touch will remain.

Also, by this invention, the ends of the knuckle 8 are cut outcircumferentially and have circular leather inserts I9 which makecontact with shoulders M of repetition lever 6.

As a modified form, strips of leather 20 may be placed on shoulders Iand the knuckle 8 may be completely of rigid material as shown in Figure4. Either of these forms prevent clatter upon contact between theknuckle and repetition lever.

Other means have been devised to maintain the sensitive touch after longusage and to prevent the breakage of parts, but it is believed that noneso simple and inexpensive as that herein described has been invented ordiscovered.

What is claimed as new and is desired to be secured by Letters Patentis:

1. In a grand piano escapement action, a wippen, a jack pivoted in oneend of said wippen and a repetition lever pivoted on said wippen, saidlever having an opening in one end, the jack having a padded headprojecting through said opening, a hammer stem pivotally supported atone end and above said lever, and having a hammer at the other end, aknuckle on said stem adjacent the pivoted end, said knuckle having arigid portion over said jack head adapted to be struck thereby uponoperation of the action and to slide therefrom after impact, saidknuckle tending to contact the lever during a part of said operation,and means between said knckle and lever to deaden the sound of contact.

2. In a grand piano escapement action, a wippen, a jack pivoted in oneend of said wippen and a repetition lever pivoted on said wippen, saidlever having an opening in one end, the jack having a padded flattenedtop, head projecting through said opening, a hammer stem pivotallysupported at one end and above said lever and having a hammer at theother end, a knuckle on said stem adjacent the pivoted end, said knucklehaving a rounded rigid portion above said flattened top jack headadapted to be struck thereby upon operation of the action and to slidetherefrom after impact, said knuckle tending to contact the lever duringa part of said operation and means between said knuckle and lever todeaden the sound of contact.

3. In a grand piano escapement action, a wippen, a jack pivoted in oneend of said wippen and a repetition lever pivoted on said wippen, oneend of said lever having a shoulder on each side thereof, the jackhaving a padded head projecting between said shoulders, a hammer stempivotally supported at one end and above said lever and having a hammerat the other end, a knuckle on said stem adjacent the pivoted end, saidknuckle having a rounded rigid portion over said jack head adapted to bestruck thereby upon operation of the action and to slide therefrom afterimpact, said knuckle tending to contact the shoulders of said leverduring a part of said operation, and padding between said shoulders andknuckle to deaden the sound of contact.

4. In a grand piano escapement action, a wippen, a jack pivoted in oneend of said wippen and a repetition lever pivoted on said wippen, oneend of said lever having a shoulder on each side thereof, the jackhaving a padded head projecting between said shoulders, a hammer stempivotally supported at one end and above said lever and having a hammerat the other end, a knuckle on said stem adjacent the pivoted end, saidknuckle having a rounded rigid portion over said jack head adapted to bestruck thereby upon operation of the action and to slide thereirom'after impact, said knuckle tending to contact the shoulders of said leverduring a part of said operation, said knuckle having padded end portionsto bear upon said shoulders to deaden the sound of contact of saidknuckle on said shoulders.

5. In a grand piano escapement action, a wippen, a jack pivoted in oneend of said wippen and a repetition lever pivoted on said wippen, oneend of said lever having a shoulder on each side thereof, the jackhaving a padded head projecting between said shoulders, a hammer stempivotally supported in one end above said lever and having a hammer atthe other end, a knuckle on said stem adjacent the pivoted end, saidknuckle having a rounded rigid portion over said jack head adapted to bestruck thereby upon operation of the action and to slide therefrom afterimpact, said knuckle tending to contact the shoulders of said leverduring a part of said operation, said shoulders having pads thereonbetween the shoulders and knuckle to deaden the sound of contact.

REINHARD SCHULZE.

